It is not uncommon for a chocolate bar or chocolate / fudge covered cookies to be opened and the chocolate is no longer shiny. Instead, fudge covered cookies look as if the chocolate has spoiled and is covered with white or light brown colored splotches. While it may appear that the chocolate has spoiled, the chocolate is in fact edible.
What has occurred is the chocolate has undergone a process called a “bloom.” There are two main types of chocolate bloom. The first is sugar bloom and the second fat bloom. Each has different causes. However, no matter the type of bloom, the surface of the chocolate will have a mottled or hazy look.
A sugar bloom happens when the chocolate or fudge covered cookies are exposed to moisture. This can happen if your cookies are in a humid environment or if you put them in the fridge and then put them on the counter at room temperature for a period and then moisture may occur.
A fat bloom is caused by exposing the fudge covered cookies to warm temperatures during the journey from the factory to you. This might happen during transit, during storage in the grocery store or warehouse, or if they sit on the counter when it's a warm in your home.